Imaging and illumination engine for an optical code reader

ABSTRACT

An imaging and an illuminating engine is provided for an optical code reader to image and illuminate remote target indicia. The engine includes an image sensor for receiving reflected illumination from the remote indicia and at least two illumination assemblies for providing illumination of the remote indicia. Each illumination assembly is capable of providing a number of different outputs, such as light having different wavelengths or different output durations. A transmissive, optical element overlays the engine for preventing light generated by the at least two illumination assemblies from reflecting back towards the image sensor. The imaging engine is an integrated circuit package for easily inserted and interfacing within an optical code reader as a plug-and-play component.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 10/633,061, filed on Aug. 1, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to imaging in optical code reading devices.Aspects of the invention are particularly useful in solid-state opticalcode readers for illuminating and imaging remote target indicia, such asan optical code. The present invention is useful in CCD based bar codereaders, and other imaging devices.

2. Description of the Related Art

Optical codes are patterns made up of image areas having different lightreflective or light emissive properties, which are typically assembledin accordance with a priori rules. The term “barcode” is sometimes usedto describe certain kinds of optical codes. The optical properties andpatterns of optical codes are selected to distinguish them in appearancefrom the background environments in which they are used. Devices foridentifying or extracting data from optical codes are sometimes referredto as “optical code readers” of which barcode scanners are one type.Optical code readers are used in fixed or portable installations in manydiverse environments such as in stores for checkout services, inmanufacturing locations for workflow and inventory control and intransport vehicles for tracking package handling. The optical code canbe used as a rapid, generalized means of data entry, for example, byreading a target barcode from a printed listing of many barcodes. Insome uses, the optical code reader is connected to a portable dataprocessing device or a data collection and transmission device.Frequently, the optical code reader includes a handheld sensor that ismanually directed at a target code.

Most conventional optical scanning systems are designed to readone-dimensional barcode symbols. The barcode is a pattern ofvariable-width rectangular bars separated by fixed or variable widthspaces. The bars and spaces have different light reflectingcharacteristics. One example of a one-dimensional barcode is the UPC/EANcode used to identify, for example, product inventory. An example of atwo-dimensional or stacked barcode is the PDF417 barcode. A descriptionof PDF417 barcode and techniques for decoding it are disclosed in U.S.Pat. No. 5,635,697 to Shellhammer et al., and assigned to SymbolTechnologies, Inc., which is incorporated herein by reference. Anotherconventional optical code is known as “MaxiCode.” It consists of acentral finder pattern or bull's eye center and a grid of hexagonssurrounding the central finder. It should be noted that the aspects ofthe inventions disclosed in this patent application are applicable tooptical code readers, in general, without regard to the particular typeof optical codes, which they are adapted to read. The inventiondescribed may also be applicable to some associated image recognition oranalysis.

Most conventional laser scanning systems generate one or more beams oflaser light, which reflects off a barcode symbol, and back to thescanning system. The system obtains a continuous analog waveformcorresponding to the light reflected by the code along one or more scanlines of the system. The system then decodes the waveform to extractinformation from the barcode. A system of this general type isdisclosed, for example, in U.S. Pat. No. 4,251,798, assigned to SymbolTechnologies, Inc. A beam scanning system for detecting and decoding oneand two-dimensional barcodes is disclosed in U.S. Pat. No. 5,561,283also assigned to Symbol Technologies, Inc.

Typically, a laser beam generated by a laser source, for example, a gaslaser tube or a semiconductor laser diode, is optically focused by anoptical train into a generally circular laser beam spot on a symbol. Thebeam spot is swept by a scanning component over the symbol and forms ascan pattern thereon. Laser light reflected off the symbol is detectedby a light sensor, e.g. a photodiode, mounted together with the lasersource, the optical train, the scanning component, and the photodiode ina housing, preferably one having a handle to enable hand-held, portableoperation.

The symbol itself is a coded pattern comprised of a series of bars ofvarious widths, the bars being spaced apart from one another to boundspaces of various widths, the bars and spaces having differentlight-reflective properties. Although dimensions may vary, depending onthe particular application and the density of the symbol, each bar andspace of a UPC symbol typically used in the retail industry to identifyretail products measures on the order of thousandths of an inch (mils).In practice, the generally circular laser beam spot has across-sectional diameter on the order of 6 to 10 mils.

Barcodes can also be read by employing imaging systems having an imagesensor and a plurality of illuminating devices for illuminating thefield of view. The image sensor generally includes a two-dimensionalarray of cells or photo sensors which correspond to image elements orpixels in the field of view. The image sensor may be a two-dimensionalor area charge coupled device (CCD) and associated circuits forproducing electronic signals corresponding to a two-dimensional array ofpixel information for a field of view.

Laser scanning and imaging systems generally include a handheld unitthat is manually pointed at the target during a scanning or imagingprocedure. The handheld unit is often a component of a much largersystem including other scanners, computers, cabling, data terminals,etch Such systems are frequently designed and constructed based onmechanical and optical specifications for the scanning engine, sometimescalled “form factors.” One such form factor is the SE900 form factorutilized by Symbol Technologies, Inc. Accordingly, there is a need toprovide a compact imaging engine that can be substituted forconventional laser line scanning engines in currently designed andcurrently deployed optical code reader systems.

There is another need to provide an imaging engine that can besubstituted for predetermined form factor scanning engines, such as theSE900 form factor scanning engine, in currently designed and currentlydeployed optical code reading systems to increase the reliability,versatility, and target working range of such systems.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an imaging enginefor use with mobile and stationary optical code readers.

It is another object of the present invention to provide an imagingengine that includes an image sensor and an illumination assembly in amodular, integrated circuit package.

It is another object of the present invention to provide an imagingengine that is simple and inexpensive to manufacture.

It is yet another objective of the present invention to provide animaging engine that is fabricated from a semiconductor material whereinthe image sensor and illumination assembly are fabricated integrallywith a base member to form an integrated circuit package.

Another object of the present invention is to provide an imaging enginewhere in its simplest form includes an illumination assembly having oneilluminating device for illuminating an entire field of view of theimaging engine.

It is a further object of the present invention to provide anillumination assembly that includes at least one illuminating device,such as an LED, a flash-type illumination module, and laser.

It is also an object of the present invention to provide an optical codereading system having at least two illumination assemblies configuredfor illuminating a field of view according to various timings.

It is another object of the present invention to provide an optical codereading system having at least one illumination assembly external to anoptical code reader.

According to the above objects, an imaging engine for optical codereaders is herein disclosed in accordance with the present inventionthat is configurable and adaptable for use in mobile and stationaryoptical code readers. Advantageously, the imaging engine is configuredand dimensioned to fit within a predetermined form factor, such as theSE900 form factor.

In a first embodiment, the imaging engine includes a substrate having abase member wherein several components of the imaging engine are placedthereon. An image sensor is located on a face of the base member and ispreferably aligned with an optical beam path of the optical code reader.The image sensor may be of a known type, such as a CCD or anothersuitable detector type, that is selected to cooperate with the imagingengine and, in particular, with an illumination assembly. Theillumination assembly is also located on a face of the base member andincludes one or more, i.e., at least one, illuminating devices forgenerating at least one output wavelength. Preferably, the illuminationassembly and the image sensor are oriented along the optical beam pathof the optical code reader. The at least one illuminating devicegenerates a corresponding number of outputs. These outputs may includevisible light and infrared radiation. In its simplest form, theillumination assembly includes one illuminating device for generating onoutput wavelength for illuminating the optical target and generating areflected light signal that is impinged on the image sensor.

Other configurations include generating a separate targeting beam foraligning the optical code reader with the optical code, and especially,the reflected light signal, generating an output for use in cooperationwith a range determining means, or generating an output for use incooperation with a focusing means.

Internal to the base member are conductive interconnections fortransferring signals from the illumination assembly and image sensor toan interface assembly. Recesses are formed on at least one face of thebase member for receiving the image sensor and the illuminationassembly. Preferably, each recess will include a means for easilyinserting or removing the image sensor or illumination assembly, therebyproviding an easily configurable imaging engine. In addition, theimaging engine includes a microprocessor cooperatively coupled to eachillumination assembly and each image sensor via the interface assemblyfor controlling the output of each illumination assembly, and fortransferring data between the imaging engine and circuitry in theoptical code reader.

A substantially transparent optical window is included and covers therecess of each illumination assembly wherein the illuminating devicesare substantially flush with the optical window to reduce reflectedlight when each illuminating device is turned on to generate an output.This optical window may be of unitary construction with an openingconfigured and adapted to align with the recess of the image sensorthereby covering each illumination assembly, or a number of opticalwindows that correspond to the number of illumination assemblies may beused wherein the reflected light that impinges on the image sensor isnot degraded by the optical window.

A non-conductive casing is provided for housing and protecting theimaging engine. Further still, the casing provides interconnections fortransferring data between the imaging engine and circuitry of theoptical code reader, and also a mounting means for attaching the imagingengine to the optical code reader. Data transfer between the imagingengine and circuitry of the optical code reader may be accomplishedusing electrical, optical, or wireless transfer mechanisms.

A second embodiment of the imaging engine is further disclosed whereinthe base member is formed from at least one semiconductor material. Inthis embodiment of the imaging engine, each image sensor and eachillumination assembly are integral with the base member having beenformed with the base member during the fabrication process. Themicroprocessor, interface assembly, and interconnections between thevarious components are also integrally formed in the semiconductor basemember. In this embodiment, the separate components of the firstembodiment are incorporated into the semiconductor base member while theimaging engine functions as discussed hereinabove.

Methods of using the imaging engine of the present invention aredisclosed wherein an operator, using a mobile or stationary optical codereader, aims the optical code reader at a selected optical code and theoptical code is illuminated with either visible light or infraredradiation from the imaging engine. One of the outputs, a targeting beam,may be used for aligning the image sensor with the optical code.Preferably, the targeting beam is received by optical code reader andcircuitry in the optical code reader automatically determines when thealignment is correct and further illuminates the optical code togenerate a reflected light signal. In a manual mode of operation, theoperator uses visual and/or audible indications to determine when thealignment is correct before initiating the step of generating thereflected light signal. In either mode of operation, the reflected lightsignal impinges on the image sensor wherein it is processed by the imagesensor, a microprocessor, and circuitry in the optical code reader.

Further disclosed is an imaging system for cooperative use with anoptical code reader. As with the imaging engine, the imaging system isconfigurable and adaptable for use with both mobile and stationaryoptical code readers. The imaging system of the present inventionincludes an imaging engine located in an optical code reader and anillumination assembly that is operatively connected to circuitry in theoptical code reader. Internal and external placement of the illuminationassembly is envisioned while still maintaining communication between theillumination assembly and circuitry of the optical code reader.

The illumination system includes at least one illuminating devicewherein each illuminating device may be an LED, a laser, an incandescentilluminating element or a gas-filled tube. LEDs and incandescentelements are known in the art. Laser devices include semiconductorlasers such as edge-emitting injection lasers or VCSELs. Gas-filledtubes include those filled with xenon that are commonly used inelectronic flash devices or other gases to generate a laser output.Preferably, the output of the illumination assembly is controlled bycircuitry in the optical code reader and may include a random orrepeating pattern of outputs in the visible and/or invisible lightrange.

In another embodiment, an optical code reading system includes anoptical code reader, an imaging engine, and at least two illuminationassemblies configured for illuminating a field of view according tovarious timings. Included with the optical code reader is associatedcircuitry for interfacing and communicating with each illuminationassembly and the imaging engine. The imaging engine is configured anddimensioned to fit within a predetermined form factor, such as the SE900form factor, of the optical code reader.

A first illumination assembly of the at least two illuminationassemblies includes at least one illuminating device controllable by thecircuitry in the optical code reader for illuminating an optical targetduring a first illumination period. Preferably, the at least oneilluminating device includes a plurality of light-emitting diodesarranged in a plurality of diode clusters where each diode cluster isindependently controllable by the circuitry in the optical code reader.

A second illumination assembly of the at least two illuminationassemblies includes at least one illuminating device controllable by thecircuitry in the optical code reader for illuminating the optical targetduring a second illumination period which may or may not be identical tothe first illumination period. Preferably, the at least one illuminatingdevice of the second illumination assembly includes a flash-type moduleand/or a plurality of light-emitting diodes arranged in a plurality ofdiode clusters where each diode cluster is independently controllable bythe circuitry in the optical code reader. The circuitry may control thefirst or second illumination assemblies, such that only one of theillumination assemblies illuminates during an imaging procedure.

Methods of using the optical code reading system of the presentinvention are hereinafter disclosed. An operator, using a mobile orstationary optical code reader, aims the optical code reader at aselected optical target and the operator actuates the optical codereader to illuminate the optical target with either visible light orinfrared radiation emitted from the at least two illumination assembliesduring respective first and second illumination periods.

The output from the at least two illumination assemblies is impinged onthe optical target generating a reflected light signal that is capturedby an image sensor in the imaging engine. The reflected light signal isthen processed to generate an output data signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing objects and advantages of the present invention for animaging and illumination engine may be more readily understood by oneskilled in the art with reference being had to the following detaileddescription of preferred embodiments thereof, taken in conjunction withthe accompanying drawings in which:

FIG. 1 is a perspective view of the imaging engine in accordance withone embodiment of the present invention;

FIG. 2 is a side view of the imaging engine of FIG. 1;

FIG. 3 is a perspective view of the imaging engine of FIG. 1 accordingto another embodiment of the present invention;

FIG. 4 is a perspective view of the imaging engine of FIG. 1 accordingto yet another embodiment of the present invention;

FIG. 5 is a perspective view of the imaging engine of FIG. 1 accordingto still another embodiment of the present invention;

FIG. 6 is block diagram of an imaging system according to the presentinvention;

FIG. 7 is a side view of an optical code reading system according to anembodiment of the present invention;

FIG. 8 is a side view of a prior art illumination assembly;

FIG. 9A is a top plan view of an optical code reading system accordingto another embodiment of the present invention;

FIG. 9B is a top plan view of an optical code reading system accordingto further embodiment of the present invention;

FIG. 9C is a front view of an illumination assembly according to anembodiment of the present invention;

FIG. 9D is a front view of an illumination assembly according to anotherembodiment of the present invention;

FIGS. 10A-E are time versus intensity graphs of the first and secondillumination assemblies according to other embodiments of the presentinvention; and

FIGS. 10F-G are time versus intensity graphs where only one illuminationassembly is operational during an imaging procedure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Several embodiments of the present invention are hereby disclosed in theaccompanying description in conjunction with the figures.Advantageously, each of the embodiments of the imaging engine is adaptedto substitute for a predetermined form factor scanning engine, such asthe SE900 form factor scanning engine used in many commerciallyavailable optical code readers.

Preferred embodiments of the present invention will now be described indetail with reference to the figures wherein like reference numeralsidentify similar or identical elements. In a first embodiment asillustrated in FIGS. 1 and 2, the imaging engine of the presentinvention is generally designated as 100. As used herein, the term“distal” refers to that portion that is further from the user while theterm “proximal” refers to that portion that is closer to the user.

As shown in FIGS. 1 and 2, the imaging engine 100 includes a substrate120 that includes a base member 102 and additional components of theimaging engine 100. In a first embodiment, the substrate 120 is formedfrom suitable non-conductive material in a generally rectangularconfiguration. Although the substrate is shown as a three-dimensionalrectangle, alternate three-dimensional configurations that adequatelyhouse the additional components of the imaging engine 100 are envisionedas well. A plurality of cavities is formed in the base member 102 forhousing additional components that include an image sensor 106 and anillumination assembly 108. Internal to the base member 102 are aplurality of passages dimensioned and configured for accommodatingconductive elements that connect the image sensor 106, the illuminationassembly 108, an aiming or targeting assembly 109 and an interfaceassembly 122.

The interface assembly 122 transfers signals between the image sensor106 and circuitry in an optical code reader, such as optical code reader260 shown in FIG. 7, or other optical code readers known in the art. Theinterface assembly 122 also transfers signals between the optical codereader 260 and the illumination assembly 108, and the optical codereader 260 and the targeting assembly 109. In addition, the interfaceassembly 122 may include a microprocessor that processes received data,controls the output of each illumination assembly 108, coordinates theflow of signals amongst the various circuits, and communicates withcircuitry 212 in the optical code reader 260.

More than one image sensor 106, as disclosed and described in a U.S.Provisional Application assigned Ser. No. 60/437,959, filed on Jan. 3,2003, and more than one illumination assembly 108 may be included in theimaging engine 100 depending on the intended application of the imagingengine 100. The entire contents of U.S. Provisional Application assignedSer. No. 60/437,959, filed on Jan. 3, 2003, are incorporated herein byreference.

Additionally, image sensors 106 of different types may be employed forincreasing the versatility of the imaging engine 100. Each image sensor106 is positioned on a face of the base member 102 and is aligned withan optical beam path of the optical code reader 260 for receivingreflected light from an external target, such as a barcode or otherremote indicia. Advantageously, the imaging engine 100 is configured anddimensioned to fit a predetermined form factor, such as the SE900 formfactor, and can be configured and dimensioned for use in other opticalcode readers including mobile devices as well as stationary devices.

In a preferred configuration, the substrate 120 includes the base member102, wherein a plurality of depressions or recesses are formed toreceive a corresponding number of image sensors 106 and illuminationassemblies 108. Each depression includes at least one receptacledimensioned to receive either an image sensor 106 or an illuminationassembly 108. Using receptacles in the respective depressions allowsmodular components to be used with the imaging engine 100. Furtherstill, since the components are modular, the imaging engine 100 iseasily configurable for different applications, easily repairable byreplacing a damaged component, or easily upgradeable as improvements aremade in the underlying technologies.

Advantageously, the imaging engine of the present invention is anintegrated circuit (IC) package where all the components are placed onthe base member 102 and integrally formed as an integrated circuitpackage. Prior art imaging engines required the unit including theimaging engine to be returned to the factory or other service facilityfor servicing resulting in increased costs and reduced flexibility ofthe systems employing the prior art imaging engines. However, since theimaging engine of the present invention is a plug-and-play component,the imaging engine is easily installed or removed by the end-userpersonnel.

With reference to FIG. 7, where an optical code reading kit is shown, ifa different imaging engine is required for a particular application, theend-user merely replaces the installed imaging engine with a differentimaging engine suited for the particular application. As shown in FIG.7, an optical code reading system 200 includes the optical code reader260 that is configured and dimensioned to receive an imaging engineconforming to a predetermined form factor. An adapter 210 is preferablylocated within the optical code reader 260 and is dimensioned andconfigured to receive the imaging engine. Further still, the adapter 210includes circuitry and/or signal paths for communication between theimaging engine and the optical code reader 260. Preferably, the adapter210 is a low-insertion force type of adapter to minimize damage to theleads of the imaging engine and to transfer data to the circuitry 212provided on a logic board 214 of the optical code reader 260. Dependingon the given application for the optical code reader 260, the installedimaging engine is selected from among various plug-and-play imagingengines 220, 230, 240, or 250 wherein each imaging engine is designedand adapted for reading optical targets under different conditions oflighting, distance, type of optical target, or other given opticalcriteria.

By way of example, if the installed imaging engine is designed andadapted for use in a system for reading remote indicia at a relativelyshort range and the user requires a system for reading remote indicia ata relatively long range, the user merely removes the installed imagingengine and installs a different imaging engine designed and adapted forlonger ranges.

The installed imaging engine is readily removed or installed. If theinstalled imaging engine needs to be changed for either operationalconsiderations, for repair, or for upgrade, the operator accesses theinstalled imaging engine through an access port (not shown) on theoptical code reader 260 after removing power or turning the optical codereader 260 off. Since the installed imaging engine is a plug-and-playcomponent, the operator easily removes the installed imaging engine outof the adapter 210 without the use of excess force. Next, the operatorselects an imaging engine from among the other imaging engines 220, 230,240, or 250 that is to be installed. The selected imaging engine isinserted into the adapter 210 using a minimum amount of force since theadapter 210 is a low-insertion force type adapter.

After closing the access port, the operator then turns on, or appliespower to the optical code reader 260. Now the optical code reader 260 isready for use with the replacement imaging engine. Advantageously, eachplug-and-play imaging engine is configured and dimensioned for removaland/or installation within the form factor without the need foranti-static precautions. Essentially, each plug-and-play imaging engine,the adapter 210, and the optical code reader 260 are resistant toelectro-static discharges therefore, no special precautions such asgrounding devices are required for removal and/or insertion of theimaging engine.

Alternately, the optical code reading system 200 illustrated in FIG. 7may be configured as a kit wherein a number of plug-and-play imagingengines are included in the kit. Each included imaging engine isconfigured and adapted for a particular purpose wherein each imagingengine is particularly adapted for a given set of conditions. Theseconditions include the type of illumination used to illuminate thetarget indicia, the intensity of the illumination of the target indicia,the intensity of the background illumination of the target indicia, thedistance between the target indicia and the imaging engine, and the typeof target indicia that is to be read.

Advantageously, the kit includes predetermined form factor optical codereader 260 and at least one imaging engine, such as imaging engine 100,where each imaging engine further includes an illumination assembly.Each supplied imaging engine is configured and dimensioned to bereceived by the optical code reader 260, to communicate with thecircuitry 212 in the optical code reader 260, and to read a differentoptical quality of the target code. Thusly, the kit is flexible foraccommodating a variety of lighting conditions, target codes, and/orcombinations thereof.

All of the receptacles on the base member 102 transfer signal data toand from the interface assembly 122 via a plurality of electricallyconductive traces formed integrally with the base member 102. It ispreferred that the depressions of the base member 102 are adapted andconfigured such that each of the image sensors 106, illuminationassemblies 108, and targeting assembly 109 are disposed substantially ator just below the outer surface of the base member 102, as shown in FIG.2. This provides for a top surface of these components to besubstantially flush with the outer surface of the base member 102.

Advantageously, the substrate 120 will be disposed in a modular packagehaving at least one signal interface system 104 for interfacing with thecircuitry 212 of the optical code reader 260. A type of signal interfacesystem 104 that may be employed includes a plurality of electricallyconductive leads that interface with a correspondingly configuredreceptacle in the optical code reader 260. The signal interface systems104 also serve the function of releasably attaching the modular packageto the receptacle. Other types of signal interface systems 104 that maybe employed include optically interface systems or wireless interfacesystems.

In instances where the signal interface systems 104 do not include anattachment means for the modular package, other conventional means ofsecuring the modular package to the optical code reader 260 can be used.

Each illumination assembly 108 includes one or more, i.e., at least one,illuminating device 110 that is operatively coupled to the interfaceassembly 122 via one or more of the internal conductive elements. In itssimplest form, the image sensor 106 includes one illuminating device 110for illuminating the entire field of view. This is possible, as comparedto prior art imaging engines, because the imaging engine 100 isfabricated and packaged as a modular, integrated circuit package.

According to the present invention, the illuminating device 110 can beeither a coherent or an incoherent light source. A preferred incoherentlight source is an LED while the preferred coherent light source is alaser. Different types of lasers may be employed as an illuminatingdevice 110, such as semiconductor lasers (including LDs). Types ofsemiconductor lasers include edge-emitting injection lasers orpreferably, a vertical-cavity surface-emitting laser diode (VCSEL) asdisclosed in U.S. Pat. No. 6,024,283 to Campanelli et al. assigned toSymbol Technologies, Inc. and is hereby incorporated by reference.Hence, when a plurality of illuminating devices 110 is disposed in eachillumination assembly 108, the illumination assembly 108 includes LEDs,LDs, or a combination of LEDs and LDs.

Further, the illuminating devices 110 are preferably selected forproviding a plurality of different output wavelengths of electromagneticradiation where the majority of the output is in the visible lightregion. In addition, one or more of the illuminating devices 110 mayprovide output wavelengths in the infrared region of the electromagneticspectrum in addition to output wavelengths in the visible lightspectrum. Reflective faces may be included in each of the illuminationassemblies 108 for controlling the strength of the output and/ordirecting the output towards a specific target that is external to theillumination assembly 108.

The output of each illumination assembly 108 directed at the opticalcode is returned to the optical code reader 260 as a reflected lightsignal that is impinged on the image sensor 106. Proper alignment of theoptical code reader 260 and the optical code results in receiving areflected light signal having a maximum intensity, thereby minimizingmisreads and no-reads of the optical code or indicia.

The aiming or targeting assembly 109 located beneath the illuminationassembly 108 provides for proper alignment. The targeting assemblyincludes one or more illuminating devices 111 for propagating a beamspot or other pattern towards the optical code during an imagingoperation. The illuminating device 111 may be an LED, a laser, or othertype of illuminating device known in the art.

For illumination assemblies 108, which include a plurality ofilluminating devices 110, the output of the illuminating devices 110 mayinclude different wavelengths in the visible and/or invisible lightrange. If all of the outputs are in visible light range, it is preferredthat the respective output wavelengths of the illuminating devices 110be in discrete ranges to provide a combined output where an observercould discern the different wavelengths which correspond to differentcolors of visible light. It is contemplated that when the combinedoutput of all the illuminating devices 110 includes differentwavelengths of light representing different discernable colors of light,the combined output of each illumination assembly 108 may be constant byhaving each illuminating device 110 emitting its particular outputsimultaneously.

If more than one illuminating device 110 is disposed in eachillumination assembly 108, it is envisioned that each illuminatingdevice 110 may be turned on and off independently of the otherilluminating devices 110 thereby producing a random or fixed outputpattern of emitted light. This random or fixed output pattern of emittedlight may include infrared light as well as light within the visiblelight range of the electromagnetic spectrum. Further still, it iscontemplated that the activation of each illumination assembly 108 maybe controlled by a microprocessor in the imaging engine 100 or by thecircuitry 212 in the optical code reader 260, either manually, e.g. upondepression of the trigger, or automatically.

In the imaging engine 100 where a plurality of illumination assemblies108 is included, it is preferred that the illumination assemblies 108are positioned about the image sensor 106 to provide optimalillumination of the target.

Additionally, the outputs of each illumination assembly 108 may beselected to illuminate a remote target that is external to the opticalreader, provide an output for a focusing means, and/or provide an outputfor a range determining means. An example of a range determining meansis disclosed in U.S. Pat. No. 6,123,264 to Li et al., the contentsthereof are hereby incorporated by reference. Examples of auto-focusingmeans for handheld optical code readers are disclosed in U.S. Pat. Nos.5,796,089 and 5,920,060 to Marom, the contents thereof are herebyincorporated by reference.

Illuminating the remote target preferably includes producing a targetingbeam of visible light and/or infrared radiation that is usable inaligning the image sensor 106 with the optical beam path of the opticalcode reader 260. When the output is visible light, reflection from theoptical code indicates to an operator that the image sensor 106 iscorrectly aligned. If infrared radiation is used for the targeting beam,visual and/or audible indications on the optical code reader 260 informthe operator that the image sensor 106 is properly aligned.

Preferably, the visible light or infrared radiation targeting beamcooperates with the circuitry 212 in the optical code reader 260 andautomatically determines when the imaging sensor 106 is aligned. Afterthe alignment is determined by the operator or the optical code reader260, the imaging engine 100 is ready to generate an output for readingthe optical code or indicia.

Advantageously, each illumination assembly 108 includes a substantiallytransparent optical window 114 that permits substantially all thegenerated output of each illuminating device 110 to be directed towardsthe optical target of the code reader. If the imaging engine 100includes more than one illumination assembly 108, the optical window 114may be of unitary construction that is configured and adapted to bedisposed adjacent to each illumination assembly 108, and in particularcompletely covering the output port of each illumination assembly 108.

When the optical window 114 is unitarily formed, it defines a void thataligns with the image sensor 106. By locating the void in alignment withthe image sensor 106, the optical window 114 will not adversely affectthe light impinging on the image sensor 106 and therefore, will notdegrade the received signal data. In lieu of a unitarily formed opticalwindow 114, a plurality of optical windows 114 may be disposed on theface of the base member 102 with each optical window configured andadapted to only cover a matching illumination assembly 108. By usingmultiple optical windows 114 that only cover the illumination assemblies108, the image sensor 106 will remain uncovered thereby allowingreflected light to impinge upon the image sensor 106 without anydegradation resulting from an interceding optical component.Conventional means are used to attach the optical window 114 to the basemember 102 of the substrate 120.

Preferably, the optical window 114 is formed from a suitable andsubstantially transparent optical quality glass. Typically, the selectedoptical quality glass will have low value of reflectance, a low value ofabsorptance, and a high value of transmittance. Further still, the glassmay be selected to have specific optical properties such as differenttransmittance values for different wavelengths of light thereby allowingthe illuminating devices 110 to be matched with the optical window 114for maximum transmittance of the emitted wavelength. It is alsoenvisioned that optical grade plastic may be substituted for glass. Inthe preferred embodiment, the optical window 114 is positionedsubstantially adjacent to the illuminating devices 110 to maximize thequantity of transmitted output and therefore minimize the amount ofreflected light that can cause “flashover.”

In a conventional imaging engine, there exists a gap between the outputof an illuminating device and an optical window, thereby causing a partof the generated output to be reflected away from the target andgenerally towards the source of the output as seen in FIG. 8. Internalreflections off the optical window result in a loss of transmitted lightto the target, thereby reducing the amount of light that is received bythe image sensor from the target. These internal reflections also createraised levels of ambient light within the optical code reader that mayinterfere with distinguishing the light reflected from the target andthe ambient light within the optical code reader. Overcoming thesedrawbacks require increasing the output of the illuminating devicesand/or changing the surface materials/colors of the optical code readerto reduce the ambient light. Further still, these drawbacks result inincreasing the number of misreads and no-reads of the optical codereader. By minimizing the amount of light reflected from a spaced-apartoptical window, the present invention permits a higher percentage of thegenerated output to reach the intended target. This increases the rangeof the optical code reader, reduces power consumption of the opticalcode reader, increases accuracy and repeatability of the optical codereader, and substantially reduces the number of misreads and no-reads.

Data transfer and communications between the imaging engine 100 and theoptical code reader is accomplished via the signal interface system 104.In one form, the signal interface system 104 includes a number ofelectrically conductive elements that are accessible on at least oneexternal location of the imaging engine 100 and therefore, are incommunication with a comparably configured receptacle in the opticalcode reader 260 for signal data communication. Another method forinterfacing the imaging engine 100 and the optical code reader 260includes the signal interface system 104 having at least one opticallyconductive element 128 for exchanging data between the imaging engine100 and the optical code reader 260 as shown in FIG. 5.

It is further contemplated that the interface between the imaging engine100 and the optical code reader 260 may employ a wireless signalinterface system for the data transfer. In a wireless configuration,signal interface system 104 includes a wireless transceiver in theimaging engine 100 and a corresponding wireless transceiver in theoptical code reader 260.

Referring to FIGS. 3 and 4, examples of wireless communications areillustrated. In the embodiment shown in FIG. 3, the imaging engine 100includes an infrared assembly 124 that generates an infrared output. Theinfrared assembly 124 further includes an infrared receiver forreceiving reflected infrared signals. Information contained in thereflected infrared signals is processed by the infrared assembly 124 andis transferred to the optical code reader 260 through the interfaceassembly 122. Data from the optical code reader 260 is transferred tothe imaging engine 100 via the interface assembly 122. For maximumflexibility and compatibility, infrared communications and datatransfers preferably follow protocols established by the Infrared DataAssociation (IRDA).

An alternate wireless communication means is shown in FIG. 4 wherein theimaging engine 100 includes a radio-frequency assembly 126.Radio-frequency transmission and reception mechanisms are included inthe radio-frequency assembly 126 along with other signal processingsystems. Radio-frequency assembly 126 transmits and receives informationin the form of radio waves. Information processed by the radio-frequencyassembly 126 is transferred to the optical code reader 260 through theinterface assembly 122.

In an alternate embodiment of the imaging engine 100, the base member102 is a semiconductor formed from one or more semiconductor materialsthat are known in the art. As discussed previously, the base member 102includes at least one image sensor 106 and at least one illuminationassembly 108. Each illumination assembly 108 further includes at leastone illuminating device 110 wherein each illuminating device 110 iseither an LED or a semiconductor laser. Preferably, the semiconductorlaser is a LD such as the VCSEL type.

Since the base member 102 is a semiconductor, each imaging engine 100,including the image sensors 106 and the illumination assemblies 108, canbe manufactured as a discrete component that is packaged in anon-conductive casing having at least one signal interface system 104that interconnects the imaging engine 100 with the optical code reader260.

Each illumination assembly 108 generates a number of outputs that aredetermined by the number of illuminating devices 110 included in eachillumination assembly 108. One or more of the outputs may be in theinfrared range for illumination of the target, supplying an output for arange determining means, supplying an output for an auto-focusing means,or supplying an output for transferring signal data to the optical codereader 260. Alternately, the illumination assembly 108 may produce oneor more outputs in the visible light range as discussed in the previousembodiment. However, the LEDs and/or LDs of the previous embodiment werediscrete components disposed in the base member 102. In this embodiment,the LEDs and LDs are formed in the semiconductor base member 102 whereintheir outputs are directed towards one or more faces of the imagingengine 100 depending on their function.

By way of example only, an illumination assembly 108 may include aninfrared LED, a red LED, and a red LD formed as integral components ofthe semiconductor base member 102. In this example, the output of theinfrared LED may be oriented to transmit data signals to a correspondinginfrared receiver in the optical code reader 260, while the red LED maybe positioned so that its output is directed in a different directionfor illuminating a remote target and the red LD is oriented in the samedirection as the red LED.

Although it may seem redundant to have both the red LED and the red LDoutputs oriented in the same direction, operational considerations mayrequire the use of the red LED in certain circumstances while the red LDis preferred under different conditions for the same optical codereader. The output of each illumination assembly 108 that is directed atthe optical code is returned to the optical code reader 260 as thereflected light signal that impinges on the image sensor 106. Properalignment of the optical code reader 260 and the optical code results ina reflected light signal with its maximum intensity thereby minimizingmisreads and no-reads of the optical code.

Interconnections among the image sensor 106, the illumination assembly108, and signal interface system 104 for transferring signal data areincorporated into the semiconductor base member 102 during manufacturingand are therefore integral to the imaging engine 100. As in the previousembodiment, the interconnections permit signals to be transferredbetween the image sensor 106 and the optical code reader 260 via thesignal interface system 104 and between the illuminating devices 110that are included in the illumination assembly 108 and the optical codereader 260 through the signal interface system 104.

Data transfer and communications between the imaging engine 100 and theoptical code reader 260 is accomplished via the signal interface system104. In one configuration, signal interface system 104 includes a numberof electrically conductive elements that are accessible on at least oneexternal location of the imaging engine 100 and therefore are incommunication with a comparably configured receptacle in the opticalcode reader 260 for signal data communication. Additionally, theconductive elements of the signal interface system 104 releasably attachthe imaging engine 100 to the receptacle in the optical code reader 260.

Another method for interfacing the imaging engine 100 and the opticalcode reader 260 includes providing signal interface system 104 with atleast one optical interface system for exchanging data between theimaging engine 100 and the optical code reader 260. It is furthercontemplated that the interface between the imaging engine 100 and theoptical code reader 260 may employ a wireless signal interface system104 for the data transfer. In a wireless configuration, signal interfacesystem 104 includes a wireless transceiver in the imaging engine 100 anda corresponding wireless transceiver in the optical code reader 260.Examples of wireless communication media include radio-frequencycommunications and infrared communications. Conventional methods forreleasably attaching the imaging engine 100 to the optical code reader260 are envisioned when the signal interface system 104 includesoptically conductive elements or a wireless arrangement.

Advantageously, each illumination assembly 108 includes a substantiallytransparent optical window 114 that permits substantially all thegenerated output of each illuminating device 110 to be directed towardsthe optical target of the code reader. If the imaging engine 100includes more than one illumination assembly 108, the optical window 114may be of unitary construction that is configured and adapted to bedisposed adjacent to each illumination assembly 108, and in particularcompletely covering the output port of each said illumination assembly108. When the optical window 114 is unitarily formed, it defines a voidthat aligns with the image sensor 106. By locating the void in alignmentwith the image sensor 106, the optical window 114 will not adverselyaffect the light impinging on the image sensor 106 and therefore willnot degrade the received signal data.

In lieu of a unitarily formed optical window 114, a plurality of opticalwindows 114 may be disposed on the face of the base member 102 with eachoptical window configured and adapted to only cover a matchingillumination assembly 108. By using multiple optical windows 114 thatonly cover the illumination assemblies 108, the image sensor 106 willremain uncovered, thereby allowing reflected light to impinge upon theimage sensor 106 without any degradation resulting from an intercedingoptical component. Conventional means are used to attach the opticalwindow 114 to the base member 102 of the substrate 120.

Preferably, the optical window 114 is formed from a suitable andsubstantially transparent optical quality glass. Typically, the selectedoptical quality glass will have low value of reflectance, a low value ofabsorptance, and a high value of transmittance. Further still, the glassmay be selected to have specific optical properties, such as differenttransmittance values for different wavelengths of light, therebyallowing the illuminating devices 110 to be matched with the opticalwindow 114 for maximum transmittance of the emitted wavelength. It isalso envisioned that optical grade plastic may be substituted for glass.In the preferred embodiment, the optical window 114 is positionedsubstantially adjacent to the illuminating devices 110 to maximize thequantity of transmitted output, and therefore minimize the amount ofreflected light.

In a conventional imaging engine 408, there exists a gap between theoutput of an illuminating device 410 and an optical window 414, therebycausing a part of the generated output to be reflected away from thetarget and generally towards the source of the output, as shown byarrows “A1” and “A2” in FIG. 8. Internal reflections off of the opticalwindow 414 result in a loss of transmitted light to the target, therebyreducing the amount of light that is received by the image sensor fromthe target and also create raised levels of ambient light within theoptical code reader that may interfere with distinguishing the lightreflected from the target and the ambient light within the optical codereader. Overcoming these drawbacks require increasing the output of theilluminating devices 410 and/or changing the surface materials/colors ofthe optical code reader to reduce the ambient light. Further still,these drawbacks result in increasing the number of misreads and no-readsof the optical code reader.

By minimizing the amount of light reflected from a spaced apart opticalwindow, the present invention permits a higher percentage of thegenerated output reaches the intended target therefore increasing theefficiency of the imaging engine that allows for increased range of theoptical code reader, reduced power consumption of the optical codereader, or increased accuracy and repeatability of the optical codereader due to minimizing the number of misreads and no-reads of theoptical code reader.

A method of using either embodiment of the imaging engine 100 ishereinafter disclosed. Maximum flexibility is achieved since eitherembodiment is configurable and adaptable for use in both mobile andstationary optical code readers. Reading a remote target indicium usingthe imaging engine 100 of the present invention includes the followingsteps. An operator using the optical code reader 260 which includes theimaging engine 100 aims the optical code reader 260 at the desiredremote optical target such as a barcode located on an object. Aiming theoptical code reader 260 may include actuating a targeting beam of light(including infrared radiation).

The targeting beam of light is generated and propagated by the targetingassembly 109. The targeting beam of light, in conjunction with thecircuitry 212 in the optical code reader 260, indicates to the operatorthat the image sensor 106 is properly aligned with the optical beam pathof the optical code reader 260. Once aligned, the image sensor 106receives the maximum quantity of the reflected light signal from thetargeted optical code. An indication that the image sensor 106 isproperly aligned includes visual observation of the targeting beam oflight on the optical code.

In addition, the optical code reader 260 may generate visual and/oraudible indications when using visible light or infrared radiation asthe targeting beam. By properly aligning the image sensor 106 with thereflected light signal in this manner, the imaging engine 100 minimizesthe number of misreads and no-reads of the optical code. Once the imagesensor 106 is properly aligned, the operator initiates the acquiringfunction of the optical code reader 260. Preferably, the targeting beamcooperates with the circuitry 212 in the optical code reader 260 todetermine when the image sensor 106 is properly aligned andautomatically initiates the acquiring function of the optical codereader 260.

Acquiring the optical code includes actuating the illumination assembly108 to illuminate the optical code by generating at least one output bythe one or more illuminating devices 110. Each output is preferably inthe visible light range corresponding to a particular color ofdiscemable light or in the infrared region of the electromagneticspectrum. The output can be determined by the optical code to be readand the design of the image sensor 106 that is included in the imagingengine 100. Since the image sensor 106 is aligned to receive thereflected light signal, the image sensor 106 receives the maximumimpingement of the reflected light signal. The image sensor 106processes the reflected light signal and converts the data containedwithin the reflected light signal into a data signal that is transferredto the circuitry 212 within the optical code reader 260.

An imaging system 300 according to the present invention is hereinafterdisclosed with reference to the block diagram of FIG. 6. The imagingsystem 300 includes an imaging engine 302 and an illumination assembly304. Furthermore, the imaging system 300 is configured and dimensionedto fit within a predetermined form factor, such as the SE900 formfactor. The imaging engine 302 may be one of the types already known inthe art or it may be one of the types previously disclosed in theinstant application. In addition, the illumination assembly 304 of theimaging system 300 may be integral with the imaging engine 302 aspreviously disclosed, or, preferably is a separate component that isconfigured and adapted to cooperate with the selected imaging engine302. When the illumination assembly 304 is a separate component it maybe placed inside the optical code reader 260 or externally attached tothe optical code reader 260. In both of the above-mentionedconfigurations, the illumination assembly 304 interfaces with thecircuitry 212 of the optical code reader 260 and/or the imaging system300.

Preferably, the imaging system 300 is controlled by a microprocessor308. The microprocessor 308 is included in the imaging system 300, asshown in FIG. 6, or may be external to the imaging system 300. Themicroprocessor 308 has communication data paths between (1) itself andthe illumination assembly 304, (2) itself and the circuitry 212 in theoptical code reader 260, and (3) itself and the imaging engine 302.Preferably, the microprocessor 308 controls the illumination assembly304 and the imaging engine 302.

Each illumination assembly 304 includes at least one illuminating device306. Each illuminating device 306 is selected from the group consistingof LEDs, lasers, incandescent illuminating elements, and gas-filledtubes. LEDs and incandescent illuminating elements are known in the art,while lasers include semiconductor edge-emitting injection lasers orVCSELs. Illuminating elements 306 of the gas-filled tube type includethose filled with a gas, such as xenon, that is typically used inelectronic flash devices.

In the imaging system 300 of the present invention, the illuminationassembly 304 may disposed adjacent to the imaging engine 302 or may bedisposed in another location of the optical code reader 260. Thesealternate locations for the illumination assembly 304 include theinterior and the exterior of the optical code reader 260 with eachlocation providing an interface between the illumination assembly 304and the microprocessor for transferring signal data. Regardless of itslocation relative to the imaging engine 302, the illumination assembly304 is disposed so that its output illuminates a selected target and thelight reflected from the target is received by the optical code reader260 and, more particularly, the imaging engine 302 of the optical codereader 260. Additionally, the optical code reader 260 may include ameans for auto-focusing and/or a means for determining the distancebetween the optical code reader 260 and a target. In these instances,the output from the illumination assembly 304 may be used to supply someor all of the incident light used in conjunction with a distancedetermining means and/or an auto-focusing means.

Alternately, the illumination assembly 304 includes a plurality ofilluminating devices 306 whose output is substantially in the visiblelight range. In this configuration, the illumination assembly 304 has anoutput that includes several different wavelengths in the visible lightrange. If all of the outputs are in visible light range, it is preferredthat the respective output wavelengths of the illuminating devices 306be in discrete ranges to provide a combined output where an observer isable to distinguish between the different wavelengths that correspond todifferent colors of visible light.

When the total output of all the illuminating devices 306 includesdifferent wavelengths of light representing different discernable colorsof light, the total output of each illumination assembly 304 may beconstant in that each illuminating device 306 emits its particularoutput simultaneously. If more than one illuminating device 306 isdisposed in each illumination assembly 304, it is envisioned that eachilluminating device 306 may be turned on and off independently of theother illuminating devices 306, thereby producing a random or repeatingoutput pattern of emitted light. This random or repeating output patternof emitted light may include infrared light as well as light within thevisible light range of the electromagnetic spectrum.

A method of using the imaging system 300 is hereinafter disclosed.Maximum flexibility is achieved since the imaging system 300 isconfigurable and adaptable for use in both mobile and stationary opticalcode readers. Reading a remote target indicium using the imaging system300 of the present invention includes the following steps. An operatorusing an optical code reader, such as the optical code reader 260, thatincludes the imaging system 300 aims the optical code reader at thedesired remote optical target such as a barcode located on an object.Aiming the optical code reader may include actuating a targeting beam oflight (including infrared radiation) using an aiming and targetingassembly, such as aiming and targeting assembly 109, that, inconjunction with circuitry in the optical code reader, such as circuitry212, indicates to the operator that the imaging engine 302 is alignedwith the optical beam path of the optical code reader and therefore, isaligned to receive the maximum quantity of the reflected light signalfrom the target optical code. Indication that the imaging engine 302 iscorrectly aligned includes visual observation of the targeting beam onthe optical code. In addition, the optical code reader may generatevisual and/or audible indications when using visible light or infraredradiation as the targeting beam. By properly aligning the imaging engine302 with the reflected light signal in this manner, the illuminationassembly 300 minimizes the number of misreads and no-reads of theoptical code.

After the imaging engine 302 is properly aligned, the operator initiatesthe acquiring function of the optical code reader. Preferably, thetargeting beam cooperates with the circuitry in the optical code readerto determine when the imaging engine 302 is properly aligned andautomatically initiates the acquiring function of the optical codereader.

Acquiring the optical code includes actuating the illumination assembly304 to illuminate the optical code by generating at least one output.Each output may be a range of wavelengths in the visible light rangecorresponding to a particular color of discemable light or may be in theinfrared region of the electromagnetic spectrum. The output that isselected is determined by the optical code to be read and the design ofthe imaging engine 302 that is included in the imaging system 300. Sincethe imaging engine 302 is still aligned to receive the reflected lightsignal, the imaging engine 302 receives the maximum impingement of thereflected light signal. The imaging engine 302 processes the reflectedlight signal and converts the data contained in the reflected lightsignal into a data signal that is transferred to the circuitry in theoptical code reader.

In another embodiment of the present invention, an optical code readingsystem 900 is provided as shown in FIG. 9A. The optical code readingsystem 900 includes an optical code reader 500, such as optical codereader 260, configured and dimensioned to receive an imaging engine 502,a first illumination assembly 504, and a second illumination assembly506 (see FIG. 9A). The optical code reader 500 includes circuitry, suchas circuitry 212, for controlling the imaging engine 502, the firstillumination assembly 504, and/or the second illumination assembly 506.The imaging engine 502 and illumination assemblies 504, 506 arepreferably integrally formed as an integrated circuit package asdescribed above with reference to imaging engine 100. The imaging engine502 is configured as a plug-and-play imaging engine as described abovewith reference to imaging engine 100.

The first illumination assembly 504 includes at least one illuminatingdevice which may include a plurality of light-emitting diodes 520 (seeFIG. 9C). The plurality of light-emitting diodes 520 is adapted toproduce a first output beam 510 having at least one output wavelength.Depending upon the operational mode of the optical code reading system900, the circuitry in the optical code reader 500 is capable ofadjusting the first output beam 510 to include at least two differentwavelengths of light. Additionally, the circuitry is adapted to controlthe duration of the first output beam 510 defining a first illuminatingperiod.

Further still, the plurality of light-emitting diodes 520 is preferablyconfigured and arranged to form at least one diode cluster 530 in thefirst illumination assembly 504. Each diode cluster 530 includes atleast one light-emitting diode 520. When the first illumination assembly504 includes more than one diode cluster 530, the activation anddeactivation of the first illumination assembly 504 is controlled by thecircuitry to produce the first output beam 510 for a particular lengthof time defining the first illuminating period.

Each diode cluster 530 is controllable by the circuitry in the opticalcode reader 500 and is further configurable to produce the first outputbeam 510 containing one or more different wavelengths during the firstilluminating period. In embodiments where more than one diode cluster530 is included, each diode cluster 530 is independently controllable bythe circuitry in the optical code reader 500. When the firstillumination assembly 504 includes two or more diode clusters 530, eachdiode cluster 530 is independently capable of producing one or moreoutput wavelengths during the first illuminating period determined bythe circuitry in the optical code reader 500.

In the second illumination assembly 506 (see FIG. 9D), a flash-typemodule 540 is preferably included and is controllable by the circuitryin the optical code reader 500 to produce a second output beam 512 for aparticular length of time defining a second illuminating period. Thesecond output beam 512 includes at least one output wavelength. Inanother embodiment, the second illumination assembly 506 includes aplurality of light-emitting diodes 520A similar to the plurality oflight-emitting diodes 520 in the first illumination assembly 504. Theplurality of light-emitting diodes 520A is adapted to produce the secondoutput beam 512 having at least one output wavelength. Depending uponthe operational mode of the optical code reading system, the circuitryin the optical code reader 500 is capable of adjusting the second outputbeam 512 to include at least two different wavelengths of light.

Additionally, the circuitry controls the duration of the second outputbeam 512 defining a second illuminating period. Further still, theplurality of light-emitting diodes 520 is preferably configured andarranged to form at least one diode cluster 530A in the secondillumination assembly 506. Each diode cluster 530A includes at least onelight-emitting diode 520A. Each diode cluster 530A is controllable bythe circuitry in the optical code reader 500 and is further configurablefor producing the second output beam 512 with one or more differentwavelengths during the second illuminating period.

In embodiments where more than one diode cluster 530A is included, eachdiode cluster 530A is independently controllable by the circuitry in theoptical code reader 500. When the second illumination assembly 506includes more than one diode cluster 530A, the activation anddeactivation of the second illumination assembly 506 is controlled bythe circuitry to produce the second output beam 512 for a particularlength of time defining the second illuminating period. When the secondillumination assembly 506 includes two or more diode clusters 530A, eachdiode cluster 530A is independently capable of producing one or moreoutput wavelengths during the second illuminating period determined bythe circuitry in the optical code reader 500.

First and second output beams 510, 512 are combinable into a combinedoutput beam 508 (see FIG. 9A) when both first and second illuminationassemblies 504, 506 are located within the optical code reader 500. Inan alternate embodiment, the second illumination assembly 506 is placedoutside the optical code reader 500 resulting in separate first andsecond output beams 510, 512, as shown by an optical code reading system900A in FIG. 9B. When the second illumination assembly 506 is locatedoutside the optical code reader 500, it maintains communication with thecircuitry in the optical code reader 500 through an illuminationinterface or via a wireless connection. Synchronization and control ofthe first and second output beams 510, 512 or the combined output beam508 is controlled by the circuitry in the optical code reader 500 or ahost terminal of the optical code reading system 900, 900A.

The circuitry is able to control either by being preset or automaticallywhen to activate and deactivate the illumination assemblies 504, 506.The circuitry may include, for example, a photo-detector for detectingthe level of ambient lighting and for controlling the illuminationassemblies 504, 506 accordingly. Other factors or parameters forcontrolling the illumination timing and intensity of each illuminationassembly 504, 506 may include the type of code being imaged, thedistance to the code, the texture of the surface the code is imprintedon, the illuminating direction, the wavelength of the output beam(s)510, 512, 508, the maximum output intensity of at least one illuminatingdevice of each illumination assembly 504, 506, etc.

The intensity of each illumination assembly 504, 506 is controlled, forexample, by activating one or more of their respective diode clusters530, 530A. The more diode clusters 530, 530A that are activated, thehigher the intensity of the output beams 510, 512, or the combined beam508. However, it is noted, that the intensity of the output beam 508 maybe less than the intensity of a single output beam 510, 512. Forexample, only one diode cluster 530, 530A may be activated in eachillumination assembly 504, 506 thereby providing a certain outputintensity, which could be less than the output intensity if all thediode clusters 530 of the first illumination assembly 504 are activatedand the second illumination assembly 506 remains deactivated.

Referring to FIGS. 10A-10G, examples of the timing sequences areillustrated. In FIG. 10A, the circuitry in the optical code reader 500,500A turns on the first illumination assembly 504 with a resultingintensity level as indicated on the Y-axis. During the time the firstillumination assembly 504 has an output, the circuitry in the opticalcode reader 500, 500A turns on the second illumination assembly 506,thereby producing a greater intensity level as indicated on the Y-axis.At a later point in time, as indicated on the X-axis, the secondillumination assembly 506 is deactivated resulting in an essentiallyzero intensity level while the first illumination assembly 504 still hasan output. After a given period of time, the first illumination assembly504 is deactivated, thereby resulting in an essentially zero intensitylevel. The time from activation and deactivation of the firstillumination assembly 504 defines the first illuminating period, whilethe time from the activation and the deactivation of the secondillumination assembly 506 defines the second illuminating period.

With respect to the embodiments illustrated in FIGS. 10B-10E, the timefrom the activation and deactivation time of the first and secondillumination assemblies 504, 506 defines the respective first or secondilluminating period. FIGS. 10B-10E illustrate examples of other possiblecombinations of timing relationships between the first illuminationassembly 504 and the second illumination assembly 506.

In FIG. 10B, both first and second illumination assemblies 504, 506 havethe same intensity level, but the activation and deactivation times ofthe second illumination assembly 506 occur later in time than theirrespective counterparts of the first illumination assembly 504.

In another example, as seen in FIG. 10C, first and second illuminationassemblies 504, 506 again have the same intensity level. The activationand deactivation times for the first illumination assembly 504 precedethe activation time for the second illumination assembly 506. A timedelay between the deactivation time of the first illumination assembly504 and the activation time of the second illumination assembly 506 isshown.

It is possible for the second illumination assembly 506 to have anactivation time that precedes the activation time of the firstillumination assembly 504. This is exemplified in FIG. 10D. The secondillumination assembly 506 has a deactivation time that is between theactivation and deactivation times of the first illumination assembly504.

In FIG. 10E, the first and second illumination assemblies 504, 506 havesubstantially identical activation and deactivation times and thereforesubstantially identical first and second illuminating periods. Theintensity level of the second illumination assembly 506 is greater thanthe intensity level of the first illumination assembly 504.

In FIG. 10F, only the first illumination assembly 504 is activated toproduce an output wavelength. In FIG. 10G, only the second illuminationassembly 506 is activated to produce an output wavelength.

Although several examples of differing intensity levels and timingrelationships are shown, other combinations are considered to be withinthe scope and spirit of the present invention. It is furthercontemplated that the output of the first and second illuminationassemblies 504, 506 may include a plurality of different wavelengths.

Alternatively, the optical code reading system 900, 900A that includesthe optical code reader 500, 500A illustrated in FIGS. 9A and 9B may beconfigured as a kit where a number of illumination assemblies, similarto illumination assemblies 504, 506, and at least one imaging engine 502are included in the kit. Each included illumination assembly isconfigured and adapted for a particular purpose and/or a given set ofoperational conditions. These conditions include the type ofillumination used to illuminate the target indicia, the intensity of theillumination of the target indicia, the intensity of the backgroundillumination of the target indicia, the distance between the targetindicia and the imaging engine, and the type of target indicia that isto be read. Preferably, the supplied illumination assemblies and theimaging engines are configured to be plug-and-play devices designed tocooperate with the plug-and-play configuration of the optical codereader 500, 500A thereby permitting easy installation or removal by theend-user personnel.

Advantageously, the kit includes a predetermined form factor opticalcode reader 500, 500A at least one imaging engine 502, and at least twoillumination assemblies 504, 506. Each supplied illumination assemblyand imaging engine 502 is configured and adapted to be received by theoptical code reader 500, 500A to communicate with circuitry in theoptical code reader 500, 500A and to read a different optical quality ofthe target code. Thusly, the kit is flexible for accommodating a varietyof lighting conditions, target codes, and/or combinations thereof.

A method of using the optical code reader 500, 500A of the optical codereading system 900, 900A in FIGS. 9A and 9B is hereinafter disclosed.Maximum flexibility is achieved since the optical code reader 500, 500Ais configurable and adaptable for use in both mobile and stationaryimplementations. Part of the flexibility results from the optical codereader 500, 500A being adapted to work with a plurality of illuminationassemblies where at least one illumination assembly is disposed withinthe optical code reader 500, 500A.

Reading a remote target indicium using the optical code reading systemof the present invention includes the following steps. An operator usingthe optical code reader 500, 500A including the illumination assemblies504, 506, aims the optical code reader 500 at the desired remote opticaltarget, such as a barcode located on an object. Aiming the optical codereader 500, 500A may include actuating a targeting beam of light(including infrared radiation) that, in conjunction with circuitry inthe optical code reader 500, 500A indicates to the operator that theimaging engine 502 is aligned with the optical beam path of the opticalcode reader 500, 500A and therefore, is aligned to receive the maximumquantity of the reflected light signal from the target optical code.

Indication that the imaging engine 502 is correctly aligned includesvisual observation of the targeting beam on the optical code. Inaddition, the optical code reader 500, 500A may generate visual and/oraudible indications when using visible light or infrared radiation asthe targeting beam. By properly aligning the imaging engine 502 with thereflected light signal in this manner, the optical code reader 500, 500Aminimizes the number of misreads and no-reads of the optical code.

Once the imaging engine 502 is properly aligned with the optical code,the operator initiates the acquiring function of the optical code reader500, 500A. Preferably, the targeting beam cooperates with circuitry inthe optical code reader 500, 500A to determine when the imaging engine502 is properly aligned and automatically initiates the acquiringfunction of the optical code reader 500, 500A.

Acquiring the optical code includes actuating the illuminationassemblies 504, 506 to illuminate the optical code by generating atleast one output. Each output may be a range of wavelengths in thevisible light range corresponding to a particular color of discemablelight or may be in the infrared region of the electromagnetic spectrum.The output that is selected is determined by the optical code to be readand the design of the imaging engine 502 that is included in the opticalcode reader 500, 500A.

The output of the optical code reader 500, 500A may be the combinedoutput beam 508, the first output beam 510, or the second output beam512. Circuitry in the optical code reader 500, 500A is capable ofcontrolling the output of the optical code reader 500, 500A and matchingthe output to the particular target optical code to be acquired. Thenumber of different wavelengths in the output, the intensity of theoutput beam, the duration of the first and second illuminating periods,and the timing relationship between the first and second illuminatingperiods are controllable by the circuitry in the optical code reader500, 500A depending, for example, upon the operational requirements of aselected implementation of the optical code reading system 900, 900A.For example, the circuitry may predetermine, i.e., prior to initiationof an imaging procedure, that the ambient lighting is low and determinesthat a certain intensity level of the output beam is desirable. Inaccordance to this determination, during the imaging procedure, thecircuitry controls at least one of the illumination assemblies 504, 506to provide an output beam having the determined intensity level.

Since the imaging engine 502 is still aligned to receive the reflectedlight signal, the imaging engine 502 receives the maximum impingement ofthe reflected light signal. The imaging engine 502 processes thereflected light signal and converts the data contained in the reflectedlight signal into a data signal that is transferred to circuitry in theoptical code reader 500, 500A.

The described embodiments of the present invention are intended to beillustrative rather than restrictive, and are not intended to representevery embodiment of the present invention. Various modifications andvariations can be made without departing from the spirit or scope of theinvention as set forth in the following claims both literally and inequivalents recognized in law.

1. An optical code reading system comprising: an optical code readerhaving associated circuitry; an imaging engine having at least one imagesensor and configured and dimensioned to fit within a predetermined formfactor of the optical code reader; an interface for interfacing saidimaging engine with said circuitry of said optical code reader; a firstillumination assembly including at least one illuminating device forilluminating an optical target during a first illuminating period; and asecond illumination assembly including at least one illuminating devicefor illuminating said optical target during a second illuminatingperiod.
 2. The optical code reading system of claim 1, wherein thesecond illuminating period is less than, equal to, or greater than thefirst illuminating period.
 3. The optical code reading system of claim1, wherein the second illuminating period corresponds to a portion ofthe first illuminating period such that said optical target issimultaneously illuminated by said first and second illuminationassemblies during the first illuminating period.
 4. The optical codereading system of claim 1, wherein the imaging engine includes atransmissive optical element located on a face of said imaging engine.5. The optical code reading system of claim 1, wherein said imagingengine is an integrated circuit package.
 6. The optical code readingsystem of claim 1, wherein said imaging engine and at least one of thefirst and second illumination assemblies are formed as an integratedcircuit package.
 7. The optical code reading system of claim 1, furthercomprising another imaging engine configured and dimensioned to fitwithin the predetermined form factor for being interchanged with theimaging engine.
 8. The optical code reading system of claim 1, whereinthe at least one illuminating device of the second illumination assemblyis a flash-type illumination module.
 9. The optical code reading systemof claim 1, wherein at least one of said first and second illuminationassemblies is externally located from said optical code reader.
 10. Theoptical code reading system of claim 1, wherein the at least oneilluminating device of at least the first and second illuminationassemblies includes a first illuminating device and a secondilluminating device, wherein the first and second illuminating devicesprovide different output wavelengths.
 11. The optical code readingsystem of claim 1, wherein activation and deactivation of at least oneof the first and second illumination assemblies is controlled accordingto at least one of a plurality of factors during an imaging procedure.12. The optical code reading system of claim 1, wherein the at least oneilluminating device of at least one the first and second illuminationassemblies includes a plurality of illuminating devices and at least oneflash-type illumination module.
 13. The optical code reading system ofclaim 1, wherein activation of the at least one illuminating device ofat least the first and second illumination assemblies is controlled toprovide an output beam having a predetermined intensity.
 14. The opticalcode reading system of claim 1, wherein the at least one illuminatingdevice of at least the first and second illumination assemblies includesa plurality of light-emitting diodes forming at least one diode cluster.15. The optical code reading system of claim 14, wherein the at leastone diode cluster includes a first diode cluster and a second diodecluster, and wherein said first and second diode clusters are activatedand deactivated at predetermined times for providing a predeterminedintensity of an output beam.
 16. An imaging engine configured anddimensioned to fit within a predetermined form factor of an optical codereader, said imaging engine comprising: an imaging assembly including atleast one image sensor; an interface for interfacing said imagingassembly with circuitry of said optical code reader when provided withinsaid predetermined form factor of said optical code reader; a firstillumination assembly including at least one illuminating device forilluminating an optical target during a first illuminating period; and asecond illumination assembly including at least one illuminating devicefor illuminating said optical target during a second illuminatingperiod.
 17. The imaging engine of claim 16, wherein the imaging engineincludes a transmissive optical element located on a face of saidimaging engine.
 18. The imaging engine of claim 16, wherein said imagingengine is an integrated circuit package.
 19. The imaging engine of claim16, wherein the at least one illuminating device of the secondillumination assembly is a flash-type illumination module.
 20. Theimaging engine of claim 16, wherein the at least one illuminating deviceof at least the first and second illumination assemblies includes afirst illuminating device and a second illuminating device, wherein thefirst and second illuminating devices provide different outputwavelengths.
 21. The imaging engine of claim 16, wherein activation anddeactivation of at least one of the first and second illuminationassemblies is controlled according to at least one of a plurality offactors during an imaging procedure.
 22. The imaging engine of claim 16,wherein the at least one illuminating device of at least one the firstand second illumination assemblies includes a plurality of illuminatingdevices and at least one flash-type illumination module.
 23. The imagingengine of claim 16, wherein activation of the at least one illuminatingdevice of at least the first and second illumination assemblies iscontrolled to provide an output beam having a predetermined intensity.24. The imaging engine of claim 16, wherein the at least oneilluminating device of at least the first and second illuminationassemblies includes a plurality of light-emitting diodes forming atleast one diode cluster.
 25. The imaging engine of claim 24, wherein theat least one diode cluster includes a first diode cluster and a seconddiode cluster, and wherein said first and second diode clusters areactivated and deactivated at predetermined times for providing apredetermined intensity of an output beam.
 26. A method for controllingillumination of an optical target comprising the steps of: determiningat least one factor or parameter selected from the group consisting ofambient lighting, type of optical target, distance to the opticaltarget, texture of a surface the optical target is imprinted on, anilluminating direction of at least one illumination assembly, wavelengthof at least one output illuminating beam, and maximum output intensityof at least one illuminating device of said at least one illuminationassembly; and controlling activation and deactivation of said at leastone illuminating device according to the at least one determined factoror parameter for illuminating said optical target.
 27. The method ofclaim 26, further comprising the following steps prior to thecontrolling step: determining duration of at least one illuminatingperiod of said at least one illuminating device; and determiningillumination intensity of at least one output beam of said at least oneilluminating device.
 28. The method of claim 27, wherein the controllingstep comprises the step of controlling activation and deactivation ofthe at least one illuminating device for emitting the at least oneoutput beam for illuminating said optical target for a period equal tothe at least one illuminating period and at the determining illuminationintensity.
 29. The method of claim 26, wherein the at least oneilluminating device includes a plurality of light-emitting diodesforming at least one diode cluster, and wherein said controlling stepcomprises the step of controlling activation of at least one of said atleast one diode cluster according to said determining step.
 30. Themethod of claim 26, wherein the at least one illuminating deviceincludes at least one flash-type module and a plurality oflight-emitting diodes, and wherein said controlling step comprises thestep of controlling activation of at least one of said at least oneflash-type module and said plurality of light-emitting diodes accordingto said determining step.